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# Ocr f321 23 may 2013~official discussion thread Watch

1. F321 Practice.zip
Just attached some f321 practice worksheets.
2. (Original post by yodawg321)
Amount of energy needed to remove an electron from each atom in one mole in a gaseous state.

(Doubt this will come up because it came up in Jan)

Q) Define Mole
The amount of a substance that contains as many atoms (around 6.02214179 x 10^23) as there are in 12g of the C-12 isotope.
3. (Original post by yodawg321)
Amount of energy needed to remove an electron from each atom in one mole in a gaseous state.

(Doubt this will come up because it came up in Jan)

Q) Define Mole
The first ionisation energy of an element is the energy required to remove an electron from each atom in 1 mole of gaseous atoms to form gaseous 1+ ions
4. (Original post by MathsNerd1)
I'm up for any questions. Explain the properties of NaCl and F2 and why the melting point is much higher in the former than the latter.

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I'll just summarise it: basically NaCl= Giant Ionic Lattice (Ionic bonds) which has to be broken to cause melting.
F2 molecs are simple molecular lattices that have van der Waal's forces between them that need to be broken to=melting.
Ionic bonds are much stonger/have higher bond enthalpy than vdWs so NaCl= higher melting point than F2
5. (Original post by niniesta96)
The amount of a substance that contains as many atoms (around 6.02214179 x 10^23) as there are in 12g of the C-12 isotope.
Probably right, definition is use is that " A mole is the amount of substance in any compound when there are as many particles as carbon atoms in 12g of a carbon -12 isotope.
6. (Original post by niniesta96)
I'll just summarise it: basically NaCl= Giant Ionic Lattice (Ionic bonds) which has to be broken to cause melting.
F2 molecs are simple molecular lattices that have van der Waal's forces between them that need to be broken to=melting.
Ionic bonds are much stonger/have higher bond enthalpy than vdWs so NaCl= higher melting point than F2
That's not too bad but you forgot about the other properties of those compounds. Like solubility and electrical conductivity.
7. (Original post by yodawg321)
Probably right, definition is use is that " A mole is the amount of substance in any compound when there are as many particles as carbon atoms in 12g of a carbon -12 isotope.
Yeah that is the textbook def- I was more kind of paraphrasing it
8. (Original post by MathsNerd1)
That's not too bad but you forgot about the other properties of those compounds. Like solubility and electrical conductivity.
Simple Covalent Structures soluble in non-polar solvents? Because V.D.W forces form between the solvent and Cl2?
9. (Original post by MathsNerd1)
That's not too bad but you forgot about the other properties of those compounds. Like solubility and electrical conductivity.
Yeah sorry- bit too much of a summary.

NaCl: Soluble in polar solvents like water as H+ dipoles in water are attracted to Cl- and O- dipoles attracted to Na+ ions.
Only conductor when molten/dissolved - giant ionic lattiece and ionic bonds are broken so ions are free to move to constitute a current.

F2: Soluble in non-polar solvents like hexane as they form vdW's with them.
No charged pariclees that are free to move so not a conductor of electricity
10. Describe and explain (with reference to bonding and structure) the differences in the properties of graphite and diamond.
11. (Original post by yodawg321)
Simple Covalent Structures soluble in non-polar solvents? Because V.D.W forces form between the solvent and Cl2?
I know its soluble in non polar solvents such as hexane, but I'm not too sure about the second part :-/
12. (Original post by niniesta96)
Yeah sorry- bit too much of a summary.

NaCl: Soluble in polar solvents like water as H+ dipoles in water are attracted to Cl- and O- dipoles attracted to Na+ ions.
Only conductor when molten/dissolved - giant ionic lattiece and ionic bonds are broken so ions are free to move to constitute a current.

F2: Soluble in non-polar solvents like hexane as they form vdW's with them.
No charged pariclees that are free to move so not a conductor of electricity
That's all correct!
13. (Original post by MathsNerd1)
That's all correct!
Btw what subjects are you taking?/ What are you planning to apply for at uni?.... Maths?
14. (Original post by niniesta96)
Describe and explain (with reference to bonding and structure) the differences in the properties of graphite and diamond.
- High melting and boiling point as its formed of covalent bonds which require a lot of energy to break.
- Forms hexagonal layers formed of Carbon atoms but have weak intermolecular forces inbetween which are van der waals which can break easily so it is considered 'soft' and can be used as lubricants.
- Inbetween the layers there are delocalised electrons which allows it to conduct electricity.
- It is insoluble in polar and non-polar solvents as the covalent bonds are too strong to break.
-Giant covalent structure.
Diamond.
-High melting and boiling point as its formed of strong covalent bonds which require a lot of energy to break.
-Tetrahedral structure
-Used as a cutting tool on drills
-Hard because of the tetrahedral structure evenly distributing the force.
- Can't conduct electricity as there are no delocalised electrons present as they are all localised in the covalent bonds.
- Insoluble in both polar and non-polar substances.
- Giant covalent structure.

I think that's everything
15. (Original post by niniesta96)
Btw what subjects are you taking?/ What are you planning to apply for at uni?.... Maths?
I'm taking Maths, Further Maths and Chemistry and yeah I'm going on to study Maths in October at Warwick
16. (Original post by MathsNerd1)
- High melting and boiling point as its formed of covalent bonds which require a lot of energy to break.
- Forms hexagonal layers formed of Carbon atoms but have weak intermolecular forces inbetween which are van der waals which can break easily so it is considered 'soft' and can be used as lubricants.
- Inbetween the layers there are delocalised electrons which allows it to conduct electricity.
- It is insoluble in polar and non-polar solvents as the covalent bonds are too strong to break.
-Giant covalent structure.
Diamond.
-High melting and boiling point as its formed of strong covalent bonds which require a lot of energy to break.
-Tetrahedral structure
-Used as a cutting tool on drills
-Hard because of the tetrahedral structure evenly distributing the force.
- Can't conduct electricity as there are no delocalised electrons present as they are all localised in the covalent bonds.
- Insoluble in both polar and non-polar substances.
- Giant covalent structure.

I think that's everything
Good job! Covered everything the examiners would be looking for- as long as you put into prose of course!
17. oooooo revision
18. Guys I really want an a in this was 3 marks off a b and made them up in my coursework.. Havent started revising yet. Any tips on how to prepare during the next 24hours? Xxx I really need an A! (A)

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Guys I really want an a in this was 3 marks off a b and made them up in my coursework.. Havent started revising yet. Any tips on how to prepare during the next 24hours? Xxx I really need an A! (A)

Posted from TSR Mobile
past papers I guess !
20. (Original post by niniesta96)
Good job! Covered everything the examiners would be looking for- as long as you put into prose of course!
Thanks and yeah I'd put it into context at the end to make sure I get the last few marks

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